Drive control device, drive control method, and program

ABSTRACT

To prevent delay in tactile presentation timing due to the responsiveness of the tactile presentation device, and to improve the reproducibility of the tactile sense. 
     A drive control device according to the present technology includes a drive control unit that causes a drive unit that drives a tactile presentation device by a drive signal based on a tactile signal to execute a pre-drive, which is to drive the tactile presentation device in advance with respect to a rise timing of the tactile signal. By the pre-drive described above, a timing at which a tactile presentation is actually started can be brought close to a rise timing of a tactile signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 371 as a U.S.National Stage Entry of International Application No. PCT/JP2019/023277,filed in the Japanese Patent Office as a Receiving Office on Jun. 12,2019, which claims priority to Japanese Patent Application NumberJP2018-151657, filed in the Japanese Patent Office on Aug. 10, 2018,each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present technology relates to a drive control device that performsdrive control for a tactile presentation device that presents tactileinformation to a toucher on the basis of a tactile signal such as avibration signal, a method thereof, and a program.

BACKGROUND ART

In recent years, applications that give tactile stimulation by a tactilepresentation device brought into contact with human skin have been usedin various situations. Here, the term “tactile presentation” means togenerate tactile stimulation.

For example, in a mobile terminal equipped with a touch screen such as asmartphone, a touch feeling of a button is simulated by vibrating ascreen (or housing) to apply tactile stimulation to a finger at the timeof touch operation of the screen.

In music listening, a tactile presentation device is built into theheadphone housing, and tactile stimulation is given in parallel withmusic reproduction to emphasize deep bass.

In the field of computer games and virtual reality (VR), there is a casein which a tactile presentation device installed in a controllerenhances the user's immersive feeling by giving tactile stimulationinteractively in accordance with a scene in response to the useroperation.

In some amusement facilities, the realistic feeling of visitors isimproved by giving tactile stimulation in accordance with the scenes bytactile presentation devices installed in the seats of movie theatersand theme parks.

Furthermore, those in a stage of research and development include hazardprediction that causes the operator to intuitively sense the situationaround a remotely operated robot or an object by feeding back, to thecontroller at hand of the operator, vibrations received by the robot orthe object to be operated (Example: Disaster Response Robot<http://www.rm.is.tohoku.ac.jp/quince_mech/#_8>).

Moreover, in the medical field, research has been conducted to improvethe surgery accuracy by feeding back to the operator the feeling(hardness) of the endoscope forceps touching an organ when operating asurgical robot (Example: da Vinci, Surgical Assist Robot<http://techon.nikkeibp.co.jp/article/FEATURE/20150217/4044 60/?P=2>).

Here, as for the tactile reproduction device, a device having aresonance frequency at a frequency (about 100 Hz) with good sensitivityin the tactile sense of a human being such as an eccentric motor (ERM)or a linear actuator (LRA) is widely used (see Patent Document 1, forexample).

Furthermore, for the tactile signals, signals generated on the basis ofthe audio signal are sometimes used instead of signals sensed by thetactile sensor (see Patent Document 2, for example).

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2016-202486-   Patent Document 2: Japanese Patent Application Laid-Open No.    2015-53038

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

Here, the mainstream of the current tactile presentation device is aso-called vibration device in which the device itself physicallyvibrates to vibrate the human body and thus generates tactilestimulation. Vibration devices often have a large mass because they needto vibrate and sufficiently stimulate the relatively insensitive skin,and therefore they tend to be less time responsive. That is, it is knownthat even if a certain amplitude value is given as the drive voltage, ittakes long time to reach the desired amplitude from the state of 0amplitude, and that, for example, an eccentric motor requires about 100ms, and a linear actuator requires about 10 ms even if the drive voltageis temporarily overshot by using a booster circuit in combination.

Therefore, the vibration generated by these vibration devices is delayedwith respect to a drive voltage having a large amplitude change, andtherefore it is difficult to present tactile stimulation at a desiredtiming, and it is difficult to express a steep rise such as vibration ofa collision.

The present technology has been made in view of the above circumstances,and it is an object of the present technology to prevent delay intactile presentation timing due to the responsiveness of the tactilepresentation device and to improve the reproducibility of the tactilesense.

Solutions to Problems

A drive control device according to the present technology includes adrive control unit that causes a drive unit that drives a tactilepresentation device by a drive signal based on a tactile signal toexecute a pre-drive, which is to drive the tactile presentation devicein advance with respect to a rise timing of the tactile signal.

By the pre-drive described above, a timing at which a tactilepresentation is actually started can be brought close to a rise timingof a tactile signal.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit start thepre-drive at a timing corresponding to a responsiveness of the tactilepresentation device.

This makes it possible to set a timing at which a tactile presentationis actually started to a timing corresponding to a responsiveness of atactile presentation device.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit start thepre-drive at a timing corresponding to a rise height of the tactilesignal.

This makes it possible to set a timing at which a tactile presentationis actually started to a timing corresponding to a rise height of atactile signal.

In the drive control device according to the present technologydescribed above, the tactile signal is accompanied by timing-relatedinformation, which is information regarding a timing of the pre-drive,by encoding, and it is desirable that the drive control unit cause thedrive unit to execute the pre-drive on the basis of the timing-relatedinformation.

This eliminates the need for analysis of a tactile signal on thedecoding side when executing a pre-drive at an appropriate timing.

In the drive control device according to the present technologydescribed above, it is desirable that the timing-related informationinclude information indicating a rise timing of the tactile signal.

This eliminates the need for signal analysis for detecting a rise timingof the tactile signal on the decoding side when executing a pre-drive atan appropriate timing.

In the drive control device according to the present technologydescribed above, it is desirable that the timing-related informationinclude information indicating a rise height of the tactile signal.

This eliminates the need for signal analysis for detecting a rise heightof a tactile signal on the decoding side when executing a pre-drive atan appropriate timing.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit execute thepre-drive with a drive signal strength corresponding to a rise height ofthe tactile signal.

This makes it possible to prevent a delay of a presentation timing tothe toucher at the moment of the maximum amplitude at a rise portion ofa tactile signal.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit execute thepre-drive with a drive signal strength corresponding to a perceptionthreshold value related to a human tactile sense.

This makes it possible to match the timing at which a toucher starts toperceive tactile stimulation corresponding to a rise portion of atactile signal with an original timing.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit execute thepre-drive with a drive signal strength corresponding to the lowest valueof the perception threshold value.

This prevents tactile stimulation from being perceived regardless of afrequency component of a rise portion of a tactile signal.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit determine astart timing of the pre-drive in units of frames of the tactile signal.

This eliminates the need for timer management in units of samples of atactile signal when determining a start timing of a pre-drive.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit determine astart timing of the pre-drive in units of samples of the tactile signal.

This makes it possible to improve an accuracy of a start timing of apre-drive.

In the drive control device according to the present technologydescribed above, it is desirable that the drive control unit set a starttiming of the pre-drive or a drive signal strength on the basis of anoperation.

This makes it possible for a system user such as a toucher to adjust astart timing of a pre-drive and a drive signal strength.

In the drive control device according to the present technologydescribed above, it is desirable that the drive unit drive the tactilepresentation device by the drive signal amplified by an amplifier, andthe drive control unit perform control of bringing the amplifier into apower saving state on the basis of an amplitude value of the tactilesignal, and perform control of bringing the amplifier into a start-upstate on the basis of a start timing of the pre-drive.

This makes it possible to reduce power consumption caused by bringing anamplifier into a power saving state in a period other than a riseportion of a tactile signal in response to a case where a rise portionof a tactile signal exists discretely in a time direction, and to bringan amplifier into a start-up state before a start timing of a pre-drive.

In the drive control device according to the present technologydescribed above, it is desirable that the drive unit drive a pluralityof the tactile presentation devices, and the drive control unit performthe pre-drive so that a tactile presentation timing is synchronizedamong the plurality of tactile presentation devices.

This makes it possible to prevent variation in tactile presentationtiming for each tactile presentation device in a case where a pluralityof tactile presentation devices having different responsiveness is used.

In the drive control device according to the present technologydescribed above, it is desirable that the drive unit drive the pluralityof tactile presentation devices, each of which performing tactilepresentation to a different receptor of a human body, and the drivecontrol unit execute the pre-drive for each tactile presentation deviceat a drive signal strength or start timing corresponding tocharacteristics of the receptor.

This makes it possible to perform the pre-drive for each tactilepresentation device in an appropriate mode corresponding tocharacteristics of a target receptor in a case where a plurality oftactile presentation devices performs tactile presentation targetingdifferent receptors of a human body.

In the drive control device according to the present technologydescribed above, it is desirable that the drive unit drive the pluralityof tactile presentation devices, and the drive control unit execute thepre-drive for each tactile presentation device with a drive signalstrength corresponding to a tactile presentation site of the tactilepresentation device in a human body.

This makes it possible to perform the pre-drive for each tactilepresentation device in an appropriate mode corresponding to tactilecharacteristics of a site of a human body in a case where a plurality oftactile presentation devices performs tactile presentation targetingdifferent sites of a human body.

Furthermore, a drive control method according to the present technologyis a drive control method including causing a drive unit that drives atactile presentation device by a drive signal based on a tactile signalto execute the pre-drive, which is to drive the tactile presentationdevice in advance with respect to a rise timing of the tactile signal.

Such drive control method also achieves similar operations to those ofthe drive control device according to the present technology.

Furthermore, a program according to the present technology is a programthat causes an information processing device to implement a function ofcausing a drive unit that drives a tactile presentation device by adrive signal based on a tactile signal to execute the pre-drive, whichis to drive the tactile presentation device in advance with respect to arise timing of the tactile signal.

Such program according to the present technology implements the drivecontrol device according to the present technology.

Effects of the Invention

According to the present technology, it is possible to prevent delay intactile presentation timing due to the responsiveness of the tactilepresentation device, and it is possible to improve the reproducibilityof the tactile sense.

Note that the effects described here are not necessarily limited, andmay be any of the effects described in the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a configuration example of a tactilereproduction system that includes a drive control device as anembodiment according to the present technology.

FIG. 2 is a diagram for explaining an internal configuration example ofan encoding device as a first embodiment.

FIG. 3 is a diagram for explaining an internal configuration example ofa drive control device as the first embodiment.

FIG. 4 is a view showing an example of a waveform of a tactile signal.

FIG. 5 is an explanatory view showing an encoding method as anembodiment.

FIG. 6 is a view showing a specific example of an encoding format as anembodiment.

FIG. 7 is a view showing an example of drive by a drive method as anembodiment.

FIG. 8 is a diagram showing an internal configuration example of anencoding unit for realizing a drive method as an embodiment.

FIG. 9 is a function block diagram of a drive control device forexplaining a function related to a drive method as an embodiment.

FIG. 10 is a flowchart showing a specific processing procedure to beexecuted in order to realize a drive method as an embodiment.

FIG. 11 is a flowchart showing a processing procedure as a firstvariation.

FIG. 12 is an explanatory view of a vibration detection threshold valuecurve.

FIG. 13 is a view of an example of drive in a second variation.

FIG. 14 is a view showing a vibration detection threshold value curvefor every receptor.

FIG. 15 is a view showing an example of a GUI for adjusting the starttiming of a pre-drive and the drive signal strength.

FIG. 16 is a diagram for explaining an internal configuration example ofthe encoding device as a second embodiment.

FIG. 17 is a diagram for explaining an internal configuration example ofthe drive control device as the second embodiment.

FIG. 18 is a view showing an example of a torso presentation typetactile device.

MODE FOR CARRYING OUT THE INVENTION

Embodiments according to the present technology will be described belowin the following order with reference to the accompanying drawings.

<1. First embodiment>

[1-1. Outline of tactile reproduction system]

[1-2. Configuration of encoding device]

[1-3. Configuration of reproduction device]

[1-4. Drive method as embodiment]

(Outline of drive method)

(Application example)

(Configuration on encoding side)

(Function configuration on decoding side)

(Processing procedure on decoding side)

[1-5. First variation]

[1-6. Second variation]

[1-7. Third variation]

[1-8. Fourth variation]

<2. Second embodiment>

[2-1. Configuration of tactile reproduction system]

[2-2. First application example]

[2-3. Second application example]

[2-4. Third application example]

<3. Variations>

<4. Summary of embodiments>

<5. Present technology>

Here, in the present description, each term is defined as follows.

Tactile stimulation: Physical phenomenon that causes a human to perceivetactile sense, such as a vibration phenomenon.

Tactile presentation: To generate tactile stimulation.

Tactile information: Information perceived by the tactile sense, such asvibration information.

Tactile signal: A signal representing a pattern of tactile stimulation,such as a signal representing a vibration waveform.

Toucher: A human who receives tactile presentation.

Tactile characteristics: Characteristics related to human tactile sense.

1. FIRST EMBODIMENT

[1-1. Outline of Tactile Reproduction System]

FIG. 1 is a diagram showing a configuration example of a tactilereproduction system 1 that includes a drive control device (reproductiondevice 3) as an embodiment according to the present technology.

First, in the present embodiment, the environment for realizing tactilereproduction is divided into a recording environment in which a tactilesignal obtained by sensing target tactile information (tactilestimulation) is encoded and encoded data Dc obtained by the encoding isrecorded, and a reproduction environment in which tactile information isreproduced on the basis of a tactile signal obtained by decoding theencoded data Dc.

As illustrated, the tactile reproduction system 1 includes, in therecording environment, a tactile sensor 5 and an encoding device 2 towhich the tactile sensor 5 is connected, and includes, in thereproduction environment, a reproduction device 3 configured to beacquirable of the encoded data Dc and a tactile presentation device 6connected to the reproduction device 3.

The tactile sensor 5 is a sensor that senses tactile stimulation, and inthis example, a vibration sensor such as a piezo pickup or anacceleration sensor is used. The tactile sensor 5 is brought intocontact with an object to be sensed, i.e., a human body in this example,to output vibration and motion as a voltage change.

The encoding device 2 includes a computer device such as a centralprocessing unit (CPU) and a digital signal processor (DSP), performsencoding in accordance with a predetermined data format regarding adetection signal (tactile signal) by the tactile sensor 5, and recordsthe encoded data Dc obtained by the encoding into a storage deviceprovided inside, for example.

The reproduction device 3 includes a computer device such as a CPU and aDSP, decodes the encoded data Dc having been acquired, and drives thetactile presentation device 6 on the basis of the tactile signalobtained by the decoding. For example, the encoded data Dc recorded inthe recording environment is acquired by the reproduction device 3 via arequired network such as the Internet. Alternatively, the encoded dataDc can be recorded on a portable recording medium, and the reproductiondevice 3 can acquire the encoded data Dc via the recording medium.

The tactile presentation device 6 is a device that generates tactilestimulation, and in this example, a vibration device such as a vibratoror an actuator is used.

The tactile presentation device 6 is attached to a predetermined site ofthe human body of the toucher so as to reproduce the tactile stimulationsensed by the tactile sensor 5.

The tactile reproduction system 1 shown in FIG. 1 is configured as asystem in which the tactile information perceived by a person wearingthe tactile sensor 5 is reproduced at the toucher, and as a systemcapable of coping with a case in which both persons are at remote placesfrom each other.

Note that FIG. 1 shows an example in which the tactile presentationdevice 6 is provided separately from the reproduction device 3, but thetactile presentation device 6 can be configured integrally with thereproduction device 3. Specifically, for example, a vibration device canbe configured to be incorporated in a portable terminal such as asmartphone.

[1-2. Configuration of Encoding Device]

FIG. 2 is a diagram for explaining an internal configuration example ofthe encoding device 2. Note that FIG. 2 also shows the tactile sensor 5shown in FIG. 1 together with an internal configuration example of theencoding device 2.

As illustrated, the encoding device 2 includes an amplifier 21, an A/Dconverter 22, a preprocessing unit 23, an encoding unit 24, a controlunit 25, a storage unit 26, a communication unit 27, and a bus BS. Thepreprocessing unit 23, the encoding unit 24, the control unit 25, thestorage unit 26, and the communication unit 27 are connected with oneanother via the bus BS so that they can communicate with one another.

The detection signal of the tactile sensor 5 is input to the amplifier21, adjusted to have an appropriate dynamic range, and then input to theA/D converter 22 for A/D conversion.

The A/D-converted detection signal (i.e., a tactile signal thatrepresents a pattern of tactile stimulation) is input to thepreprocessing unit 23. The preprocessing unit 23 performs various kindsof digital signal processing such as noise removal and calibration ofthe sensor characteristics of the tactile sensor 5.

The tactile signal subjected to the signal processing by thepreprocessing unit 23 is input to the encoding unit 24.

The encoding unit 24 includes, for example, a DSP, and encodes the inputtactile signal in accordance with a predetermined data format.

Note that the coding of the tactile signal as the present embodimentwill be described later again.

The control unit 25 includes, for example, a microcomputer having a CPU,a read only memory (ROM), and a random access memory (RAM), and performsoverall control of the encoding device 2 by executing processing inaccordance with a program stored in the ROM.

For example, the control unit 25 performs data communication with anexternal device via the communication unit 27.

The communication unit 27 is configured to be capable of performing datacommunication with an external device via a network such as theInternet, and the control unit 25 is configured to be capable ofperforming data communication with an external device connected to thenetwork via the communication unit 27. In particular, the tactile signal(the encoded data Dc described above) encoded by the encoding unit 24can be transmitted to an external device via the communication unit 27.

The storage unit 26 comprehensively represents a storage device such asa hard disk drive (HDD) or a solid state drive (SSD), and is used forvarious data storage in the encoding device 2. For example, the storageunit 26 stores data necessary for control by the control unit 25.Furthermore, on the basis of the control of the control unit 25, thetactile signal (the encoded data Dc) encoded by the encoding unit 24 canbe stored in the storage unit 26.

[1-3. Configuration of Reproduction Device]

FIG. 3 is a diagram for explaining an internal configuration example ofthe reproduction device 3, and also shows the tactile presentationdevice 6 shown in FIG. 1 together with an internal configuration exampleof the reproduction device 3. The reproduction device 3 is an embodimentof a drive control device according to the present technology.

As illustrated, the reproduction device 3 includes an amplifier 31, aD/A converter 32, a postprocessing unit 33, and a decoding unit 34, andalso includes a control unit 35, a communication unit 36, a media drive37, a storage unit 38, and an operation unit 39. The postprocessing unit33, the decoding unit 34, the control unit 35, the communication unit36, the media drive 37, and the storage unit 38 are connected with oneanother via the bus BS so that they can communicate with one another.

The control unit 35 includes, for example, a microcomputer having a CPU,a ROM, and a RAM, and performs overall control of the reproductiondevice 3 by executing processing in accordance with a program stored inthe ROM.

The communication unit 36 is configured to be capable of performing datacommunication with an external device via a network such as theInternet. The control unit 35 is configured to be capable of performingdata communication with an external device connected to the network viathe communication unit 36. In particular, the control unit 35 can causethe communication unit 36 to receive the encoded data Dc from anexternal device such as a server device on the network.

The media drive 37 is configured so that a portable recording medium isdetachable, and is configured as a reader/writer unit capable of writingand reading data into and from the mounted recording medium. Therecording media supported by the media drive 37 include a memory card(e.g., portable flash memory) and an optical disk recording medium.

The media drive 37 enables reading of the encoded data Dc recorded on aportable recording medium.

The storage unit 38 comprehensively represents a storage device such asan HDD or an SSD, and is used for various data storage in thereproduction device 3. For example, the storage unit 38 stores datanecessary for control by the control unit 35. Furthermore, on the basisof the control of the control unit 35, the encoded data Dc read by themedia drive 37 and the encoded data Dc received from an external deviceby the communication unit 36 can also be stored in the storage unit 38.

The operation unit 39 comprehensively represents various operatorsprovided in the reproduction device 3, and outputs operation inputinformation corresponding to the operation input to the control unit 35.

The control unit 35 executes processing corresponding to the operationinput information. Therefore, the reproduction device 3 realizes anoperation corresponding to the operation input.

The encoded data Dc is input to the decoding unit 34 on the basis of thecontrol of the control unit 35.

The decoding unit 34 obtains a tactile signal by decoding the inputencoded data Dc by a method described later. The tactile signal obtainedby the decoding unit 34 is input to the postprocessing unit 33.

The postprocessing unit 33 performs signal processing such ascalibration of the tactile presentation device 6 and predeterminedfilter processing as necessary on the tactile signal having been input.

The tactile signal having passed through the postprocessing unit 33 isinput to the D/A converter 32, subjected to D/A conversion, adjusted tohave an appropriate dynamic range by the amplifier 31, and then outputto the tactile presentation device 6.

Therefore, the tactile presentation device 6 is driven on the basis ofthe tactile signal, and can give the toucher the tactile stimulationthat is the target of sensing in the recording environment (i.e.,tactile information can be reproduced).

Note that only the tactile signal is mentioned above, but it is alsopossible to adopt a configuration in which an audio signal and a videosignal are recorded together with a tactile signal and sound and videoare provided to the toucher together with tactile information.

[1-4. Drive Method as Embodiment]

(Outline of Drive Method)

Here, in reproducing tactile information, it should be considered that aconsiderable response delay to the drive signal occurs in the tactilepresentation device 6. In particular, in a case where a vibration deviceis used as the tactile presentation device 6 as in the present example,there is a possibility that a relatively large response delay occurs,thereby causing a reproducibility deterioration of the tactile sense.

Therefore, in the present embodiment, it is an object to prevent delayof the tactile presentation timing due to the responsiveness (timeresponsiveness) of the tactile presentation device 6, and to improve thereproducibility of the tactile sense.

Hereinafter, a drive method as an embodiment for preventing delay ofsuch tactile presentation timing will be described.

First of all, the majority of phenomena related to tactile sense arephenomena in which temporally sparse stimulation, such as contact orcollision with a certain object, rather than phenomena in which certainstimulation is constantly continued. Therefore, as illustrated in FIG. 4for example, majority of tactile signals are those having a value thatis 0 in many sections and that rises sharply.

In consideration of this point, a description will be given below on anassumption of a tactile signal as illustrated in FIG. 4.

In this example, the encoding device 2 analyzes the tactile signal, andobtains the time of the sharp rise of the signal and the rise height.Specifically, in the waveform shown in FIG. 4, the tactile signal risessharply at times t1 and t2, respectively. These rises are each detectedby signal analysis, and rise times t1 and t2 and rise heights A1 and A2are obtained.

Here, the signal analysis for rise detection may be performed bycomparing the set threshold value with the signal strength, or may beperformed by a signal processing method such as observing the changerate of the signal strength.

As the encoding of a tactile signal, the encoding device 2 performsencoding of causing information indicating rise timing such as the timest1 and t2 and information indicating the amplitude height of each risesuch as rise heights A1 and A2 to accompany the tactile signal.

Specifically, in this example, on an assumption that the tactile signalis handled in units of frames, information indicating the rise timingand information indicating the amplitude height of the rise are causedto accompany every frame.

FIG. 5 is an explanatory view showing the encoding method as anembodiment.

As illustrated, for every frame Fr of the tactile signal, information(“T” in the figure) indicating the remaining time to the rise timeclosest to the frame Fr, and information (“A” in the figure) indicatingthe amplitude height of the rise are stored for each header section.

Hereinafter, the “remaining time to the rise time closest to the frameFr” described above is expressed as “time T until rise” and the“amplitude height of the rise” described above is expressed as “riseheight A”.

The time T until rise records, for example, the remaining time from thehead time of the frame Fr to the most recent rise time.

Note that in a case where the sampling frequency of the tactile signalis 2 kHz, one sample of the tactile signal is 0.5 ms. In this case, ifone frame Fr has 512 samples, 1 frame=256 ms.

FIG. 6 shows a specific example of an encoding format.

As illustrated, the frame Fr is provided with a header region, which isa region for storing header information, followed by a real data regionfor storing real data of the tactile signal. The header region isprovided with regions for storing information regarding the sync, thesampling frequency, the quantization bit length, the block size, thetime T until rise, and the rise height A, in order from the head side.

The sync is an identifier indicating a delimiter of the frame Fr, andstores data according to a predetermined pattern. The sampling frequencyand the quantization bit length represent the sampling frequency and thequantization bit length, respectively, of the tactile signal. The blocksize represents the size in the time direction of the tactile signalstored in the real data region, and stores information in units of thenumber of samples, for example.

The encoding device 2 (encoding unit 24) encodes the tactile signal inaccordance with the format shown in FIG. 6 to generate the encoded dataDc.

The reproduction device 3 drives the tactile presentation device 6 inadvance with respect to the rise timing of the tactile signal on thebasis of the information regarding the time T until rise and the riseheight A stored in the header of the frame Fr in the encoded data Dc.Hereinafter, to drive the tactile presentation device 6 in advance withrespect to the rise timing of the tactile signal will be referred to asa “pre-drive”.

In the reproduction device 3, the decoding unit 34 first calculates atime length required for the tactile presentation device 6 to generatevibration corresponding to the rise height A on the basis of theinformation of the rise height A. This time length can be expressed inother words as a time length of the pre-drive necessary for the tactilepresentation device 6 to generate vibration with a desired amplitude,and is hereinafter referred to as a “time length Δt”.

The time length Δt is obtained as a value based on the responsiveness ofthe tactile presentation device 6 by performing a calculation using acoefficient representing the responsiveness of the tactile presentationdevice 6 and the rise height A, for example.

Note that the coefficient representing the responsiveness of the tactilepresentation device 6 may be a predetermined value or may be acquired bycalibration.

Here, in the reproduction device 3 of this example, power saving controlof the amplifier 31 is performed on the assumption that the tactilesignal is a signal representing a generation of a temporally sparsetactile stimulation as illustrated in FIG. 4. Specifically, theamplifier 31 is controlled to a power saving state in a period ofsufficiently small amplitude existing between the rises of the tactilesignal.

It takes a certain amount of time for the amplifier 31 to start up fromthe power saving state. Therefore, in this example, when the pre-drivedescribed above is performed, the start-up control of the amplifier 31is performed before the start timing of the pre-drive. That is, wherethe time required for starting up the amplifier 31 from the power savingstate is a start-up time Δta, a control of starting up the amplifier 31in the power saving state by the start-up time Δta before the starttiming of the pre-drive is performed.

Note that the start-up time Δta may be a value obtained as a constantfrom the characteristics of the amplifier 31 itself. Alternatively, thestart-up time Δta can also be dynamically obtained with respect to therise height A.

The decoding unit 34 performs the following processing for every frameFr with respect to the encoded data Dc to be input.

That is, the sum “Δt+Δta” of a time length Δt of the pre-drive and thestart-up time Δta of the amplifier 31 is obtained. Then, it isdetermined whether or not the time T until rise is less than the sumΔt+Δta (T<Δt+Δta). Then, if T<Δt+Δta, the amplifier 31 is started upfrom the power saving state.

After the amplifier 31 is started up in this manner, it is determinedwhether or not the time T until rise has become less than the length Δtof the pre-drive time (T<Δt). Then, if T<Δt, the pre-drive is started.In this example, the amplitude of the tactile signal is assumed to bethe amplitude by the rise height A (hereinafter referred to as an“amplitude A”) at the time of the pre-drive.

FIG. 7 shows an example of drive.

According to the drive method described above, the amplifier 31 isstarted up before Δt+Δta with respect to the rise timing of the tactilesignal represented by the time t1, and for the tactile presentationdevice 6, the pre-drive is started before Δt with respect to the timet1. In this example, the amplitude of the tactile signal at the time ofthe pre-drive is the amplitude A.

By such pre-drive, the signal presented by the tactile presentationdevice 6 reaches the amplitude A at the time t1. Therefore, the timingat which the tactile stimulation has the maximum amplitude can bematched with the original timing at which the tactile signal has themaximum amplitude. That is, the moment of the maximum amplitude having alarge perceptual influence can be matched with the original time.

After the rise at the time t1, the amplifier 31 is switched to the powersaving state again in response to a sufficient attenuation of thetactile signal. As a result, the power consumption of the amplifier 31is reduced.

Here, the moment at which the time T until rise becomes 0 is theoriginal rise time, and hence the tactile presentation device 6 isdriven thereafter in accordance with the original amplitude of thetactile signal.

In the frame Fr on and after the rise time, the information regardingthe time T indicating the remaining time until a next rise time, and theinformation regarding the height A related to the next rise time arenewly stored in the header. At this time, the amplifier 31 is broughtinto the power saving state in a case where the amplitude of the tactilesignal is sufficiently small and there is a time until the next rise,specifically, for example, the time T until rise is greater than Δt+Δta.

Application Example

It is conceivable that the drive method described above is applied to acase of viewing a movie with vibration using a portable terminal such asa smartphone.

For example, let the reproduction device 3 be a portable terminal havinga built-in tactile presentation device 7 as a vibration device. Aneccentric motor is often used as a vibration device for smartphones andthe like from the viewpoint of cost. However, it takes a time of about100 ms for an eccentric motor to reach the desired amplitude from theamplitude of 0, and the responsiveness is low. Hence, even if theeccentric motor is driven using the tactile signal as it is, the tactilepresentation timing is delayed by 100 ms compared with that originallydesired. This means that the vibration is delayed more than the videoand audio of the movie, which becomes a factor that greatly spoils theuser experience.

Therefore, it is preferable to apply the drive method of the presentembodiment. In this case, the vibration of the eccentric motor isstarted 100 ms before the original signal rise timing. Furthermore, theamplifier 31 is started up, for example, 120 ms prior to it.

Therefore, even in a case where an eccentric motor having lowresponsiveness is used, it is possible to prevent the tactilepresentation timing from being delayed, and it is possible to improvethe reproducibility of the tactile sense. Furthermore, by providing atime for the amplifier 31 to be brought into the power saving state, itis possible to reduce power consumption necessary for tactilepresentation.

(Configuration on Encoding Side)

FIG. 8 is a diagram showing an internal configuration example of theencoding unit 24 for realizing a drive method as an embodiment describedabove.

As illustrated, the encoding unit 24 includes a signal analysis unit 24a and an encoded data generation unit 24 b. The signal analysis unit 24a performs a signal analysis on the tactile signal to be input from thepreprocessing unit 23 shown in FIG. 2, and obtains the “time T untilrise” and the “rise height A” for the target frame Fr.

The encoded data generation unit 24 b generates the encoded data Dc onthe basis of the tactile signal to be input from the preprocessing unit23 and the “time T until rise” and the “rise height A” obtained by thesignal analysis unit 24 a. Specifically, in accordance with the encodingformat described with reference to FIG. 6, the encoded data generationunit 24 b generates the encoded data Dc in which predeterminedinformation such as the time T until rise and the rise height A arestored in the header.

(Function Configuration on Decoding Side)

FIG. 9 is a function block diagram for explaining the function relatedto the drive method as an embodiment included in the reproduction device3.

As illustrated, the reproduction device 3 has a function as a drive unitF1 and a drive control unit F2.

The drive unit F1 drives the tactile presentation device 6 by a drivesignal based on the tactile signal, and in this example, the drive unitF1 corresponds to the D/A converter 32 and the amplifier 31.

The drive control unit F2 causes the drive unit F1 to execute apre-drive, which is to drive the tactile presentation device 6 inadvance with respect to the rise timing of the tactile signal. In thisexample, the function as the drive control unit F2 is implemented by thedecoding unit 34.

In this example, the drive control unit F2 starts the pre-drive at atiming corresponding to the responsiveness of the tactile presentationdevice 6. This makes it possible to set a timing at which a tactilepresentation is actually started to a timing corresponding to aresponsiveness of a tactile presentation device.

Furthermore, the drive control unit F2 of this example starts thepre-drive at a timing corresponding to the rise height A of the tactilesignal. This makes it possible to set a timing at which a tactilepresentation is actually started to a timing corresponding to a riseheight of a tactile signal.

Furthermore, the drive control unit F2 in this example causes the driveunit F1 to execute the pre-drive on the basis of the timing-relatedinformation accompanying the tactile signal by encoding.

Here, the timing-related information is information related to thetiming of the pre-drive, and in this example, the timing-relatedinformation corresponds to the information regarding the “time T untilrise” representing the rise timing of the tactile signal and theinformation regarding the “rise height A” of the tactile signal.

By executing the pre-drive on the basis of the timing-relatedinformation accompanying the tactile signal by encoding, it is notnecessary to analyze the tactile signal on the decoding side whenexecuting the pre-drive at an appropriate timing. That is, it ispossible to reduce the processing load on the decoding side.

Furthermore, the drive control unit F2 in this example executes thepre-drive by the drive signal strength corresponding to the rise heightA of the tactile signal.

This makes it possible to prevent a delay of a presentation timing tothe toucher at the moment of the maximum amplitude at a rise portion ofa tactile signal.

Further, in the reproduction device 3 of this example, the drive unit F1drives the tactile presentation device 6 by the drive signal amplifiedby the amplifier 31, and the drive control unit F2 performs control ofbringing the amplifier 31 into the power saving state on the basis ofthe amplitude value of the tactile signal, and performs control ofbringing the amplifier 31 into the start-up state on the basis of thestart timing of the pre-drive.

This makes it possible to reduce power consumption caused by bringingthe amplifier 31 into a power saving state in a period other than a riseportion of a tactile signal in response to a case where a rise portionof a tactile signal exists discretely in a time direction, and to bringthe amplifier 31 into a start-up state before a start timing of apre-drive. Therefore, it is possible to improve the reproducibility ofthe tactile sense by pre-drive while reducing power consumption.

Note that in this example, an example in which the drive unit F1 and thedrive control unit F2 are integrally configured in the same device asthe reproduction device 3 is described, but a configuration in which thedrive unit F1 is provided in a separate device from the drive controlunit F2 is possible.

(Processing Procedure on Decoding Side)

With reference to the flowchart of FIG. 10, the procedure of theprocessing to be executed by the reproduction device 3 in order toimplement the drive method as the embodiment described above will bedescribed.

Note that the processing shown in FIG. 10 is executed by the decodingunit 34 for every frame Fr of the encoded data Dc.

In FIG. 10, the decoding unit 34 performs in step S101 processing ofacquiring the time T until the next rise and the rise height A. That is,the decoding unit 34 acquires information regarding the time T untilrise and the rise height A stored in the header of the target frame Fr.

In subsequent step S102, the decoding unit 34 calculates the time lengthΔt of the pre-drive on the basis of the rise height A, and performs inthe next step S103 processing of acquiring the start-up time Δta of theamplifier 31. As described above, the time length Δt of the pre-drive iscalculated in this example by using the coefficient indicating theresponsiveness of the tactile presentation device 6 and the rise heightA.

Note that the start-up time Δta of the amplifier 31 can be obtaineddynamically with respect to the rise height A, and in that case, it isobtained by calculation using the height A.

In step S104, following step S103, the decoding unit 34 determineswhether or not to start up the amplifier 31, specifically, whether ornot it is “T<Δt+Δta”.

In a case where the decoding unit 34 determines that it is not“T<Δt+Δta” and the amplifier 31 should not be started up yet, thedecoding unit 34 determines in step S105 whether or not there is anonzero signal.

Here, a case where it is not “T<Δt+Δta”, i.e., a case in which there issufficient time until the next rise, is considered to be either a casein the middle of a non-signal period between rise portions of a signalor a case in the middle of a period on and after the rise timing in arise portion of a signal. The determination processing in step S105functions as processing of sorting as to which of these two cases toapply.

In a case of determining in step S105 that there is no nonzero signal(i.e., in a case of a non-signal period), the decoding unit 34 controlsin step S106 the amplifier 31 to be brought into the power saving stateand ends the series of processing shown in FIG. 10.

Therefore, in the non-signal period excluding the rise portion of thetactile signal, the amplifier 31 is prevented from unreasonablyconsuming power, thereby reducing power consumption.

On the other hand, in a case of determining in step S105 that there is anonzero signal, the decoding unit 34 outputs an input signal in stepS107. That is, the decoding unit 34 outputs the tactile signal stored inthe real data region in the frame Fr. In response to the execution ofthe output processing in step S105, the decoding unit 34 ends the seriesof processing shown in FIG. 10.

Here, the rise of the tactile signal occurs independently of the breakof the frame Fr, and it is rare that the rise timing of the tactilesignal coincides with the break of the frame Fr. Assuming that thetarget rise timing in the tactile signal is a “rise timing Tt” and thatthe frame Fr including the rise timing Tt is the m-th frame Fr(hereinafter referred to as a frame Fr(m)), in the encoding by theencoding unit 24, the “time T until rise” for the rise timing Tt isstored up to the frame Fr(m), and the “time T until rise” for the risetiming subsequent to the rise timing Tt is stored from the frame Fr(m+1) subsequent to the frame Fr(m).

According to the processing in steps from S105 to S107, in response tothe case where the frame Fr to be processed is the frame Fr (m+1), it ispossible to appropriately output the signal in the nonzero period at therise portion. Furthermore, this means that switching is appropriatelyperformed from the output of the amplitude A as the pre-drive to thesignal output in the nonzero period at the rise portion.

Subsequently, in a case of determining in the previous step S104 that itis “T<Δt+Δta” and the amplifier 31 should be started up, the decodingunit 34 performs in step S108 control of starting up the amplifier 31,and then determines in step S109 whether or not it is immediately beforerise, specifically, whether or not it is “T<Δt”.

In a case of determining that it is not “T<Δt” and it is not immediatelybefore rise, the decoding unit 34 ends the series of processing shown inFIG. 10.

On the other hand, in a case of determining that it is “T<Δt” and it isimmediately before rise, the decoding unit 34 outputs in step S110 thesignal having the amplitude A, and ends the series of processing shownin FIG. 10. Therefore, the pre-drive is performed from the frame Frwhere it has become “T<Δt” to the frame Fr(m) described above.

[1-5. First Variation]

Here, the processing shown in FIG. 10 is an example of determining thestart timing of the pre-drive in units of frames of the tactile signal.According to this, for example, if the time length of the frame Frdetermined from the number of samples included in the frame Fr and thesampling frequency (e.g., if the number of samples=128 and the samplingfrequency=2 kHz, it is 64 ms) is sufficiently short, it is possible tosufficiently exhibit the delay reduction effect of the tactilepresentation timing.

On the other hand, the determination of the start timing of thepre-drive can be performed in units of samples. Therefore, even if thetime length of the frame Fr is long, it is possible to performdetermination with high time resolution.

FIG. 11 shows an example of a specific processing procedure.

Note that in the following description, similar parts and processing tothose described so far are given the same reference numerals and thesame step numbers to avoid duplicate explanations.

In FIG. 11, the difference from FIG. 10 is that steps S202 and S203 areexecuted instead of steps S107 and S110, and steps S201, S204, and S205are added.

First, in a case of determining in step S105 that there is a nonzerosignal, the decoding unit 34 in this case executes processing ofoutputting a signal S[n] in step S202, and then proceeds to step S204.

Here, “n” is a time index indicating as to what number of the sample ofthe tactile signal, and the signal S[n] means a value of the nth sampleof the tactile signal.

In step S204, the decoding unit 34 determines whether or not the framehas ended, i.e., whether the processing has been executed up to thefinal sample of the frame Fr to be processed, and in a case ofdetermining that the frame has not ended, the decoding unit 34 executesin step S205 the processing of updating the time T until rise and thetime index n, and returns to step S104.

Here, the time T until rise is updated by “T=T−1/Fs”, where the samplingfrequency of the tactile signal is “Fs”.

Furthermore, in a case of determining in step S109 that it is “T<Δt”,the decoding unit 34 in this case determines in step S201 whether or notit is “T≤0”. This corresponds to determination as to whether or not thetime indicated by the time index n is a time on and after the targetrise time in the tactile signal.

If it is not “T≤0” in step S201, the decoding unit 34 outputs in stepS203 the amplitude A, and proceeds to step S204. Therefore, it ispossible to perform the pre-drive having the amplitude A from it becomes“T<Δt” to immediately before “T≤0”.

On the other hand, if it is “T≤0”, the decoding unit 34 outputs thesignal S[n] in step S202. Therefore, it is possible to output a nonzerosignal at the rise portion on and after the rise time.

By the processing shown in FIG. 11, it is possible to determine thestart timing of the pre-drive in units of samples of the tactile signal.

This makes it possible to improve an accuracy of a start timing of apre-drive. That is, it is possible to increase the matching accuracybetween the timing at which tactile presentation is actually started andthe original timing.

[1-6. Second Variation]

Here, in the above example, the amplitude of the tactile signal at thetime of the pre-drive is matched with the rise height A. That is, anexample in which the drive signal strength of the pre-drive is set tothe strength corresponding to the rise height A has been given.

However, in a case where it is desired to match not the moment ofmaximum amplitude but the timing at which the toucher starts to perceivethe tactile stimulation, it is effective to perform the pre-drive withan amplitude in accordance with the vibration detection threshold valuecurve as shown in FIG. 12.

FIG. 12 shows a vibration detection threshold value curve indicating astandard of the human tactile sensitivity related to vibration. Notethat in FIG. 12, the horizontal axis represents the frequency, and thevertical axis represents the magnitude of tactile stimulation(vibration: displacement here).

The vibration detection threshold value curve is an experimentallyexamined example of whether or not the human feels the vibration as atactile sense, i.e., the tactile sensitivity. The human cannot perceivevibrations smaller than this curve as a tactile sense.

Therefore, the pre-drive is performed with an amplitude equal to orsmaller than the threshold value represented by such vibration detectionthreshold value curve.

FIG. 13 shows an example of drive. As illustrated, the signal presentedin this case does not exceed the vibration detection threshold valuerepresented as a threshold value Th in the figure in the period of thepre-drive.

With such drive, the vibration is not felt at a timing earlier than theoriginal rise time t1 of the tactile signal, yet the time required toreach the desired vibration strength can be shortened compared withvibrating from the state of the amplitude 0, and hence it is alsopossible to reduce the moment of the maximum amplitude of the presentedvibration, i.e., the deviation from the time t1.

Note that although an example of the human perception threshold valuerelated to vibration as the vibration detection threshold value has beengiven, a perception threshold value similarly exists for tactilestimulation other than vibration.

In a case where the rise time for the strength of the presented tactilestimulation to reach the strength corresponding to the perceptionthreshold value is so short that it does not need to be taken intoconsideration, the time length Δt of the pre-drive can also bepredetermined as a constant value. Alternatively, the time length Δt canalso be determined in accordance with the magnitude of the perceptionthreshold value.

Here, as in the threshold value curve for vibration illustrated in FIG.12, the perception threshold value may vary depending on the frequency.In this case, the decoding unit 34 performs signal analysis on thetactile signal to specify a main frequency component of the riseportion, and executes the pre-drive with an amplitude (drive signalstrength) in accordance with a perception threshold value correspondingto the frequency component.

Alternatively, it is possible to skip specification of such a frequencycomponent, and to match the amplitude at the time of the pre-drive withthe lowest threshold value of the perception threshold values (e.g., inthe example of FIG. 12, the threshold value is matched with a thresholdvalue near 300 Hz).

[1-7. Third Variation]

The third variation relates to a method in which the characteristics ofreceptors of the human body are considered.

It is generally known that there is a plurality of receptors forperceiving tactile information beneath the human skin. Typically knownreceptors include Meissner's corpuscles (hereinafter abbreviated as“Meissner”), Merkel cells (Hereinafter abbreviated as “Merkel”), Ruffiniendings (Hereinafter abbreviated as “Ruffini”), and Pacinian corpuscles(Hereinafter abbreviated as “Pacinian”).

Meissner and Pacinian are also called “FA1” and “FA2”, respectively,where FA is an abbreviation for “Fast Adapting”. Merkel and Ruffini arealso called “SA1” and “SA2”, respectively, where SA is the abbreviationfor “Slow Adapting”.

Merkel (SA1) continues to fire its nerves while pressing an object, andis said to be detecting the strength (displacement and pressure).Meissner (FA1) is said to be detecting the speed in a section where thepush amount of an object becomes constant. Pacinian (FA2) is said to beresponsible for detection of acceleration in a section where the pushchange amount changes.

FIG. 14 shows a vibration detection threshold value curve for everyreceptor.

In the figure, a threshold value Th-m indicated by the solid linerepresents a vibration detection threshold value of Merkel, and athreshold value Th-p indicated by the dashed line represents a vibrationdetection threshold value of Pacinian. Note that the vibration detectionthreshold value curve shown in FIG. 12 does not show the characteristicsof a single receptor, but shows the synthesized characteristics oftactile sense obtained by a plurality of receptors as shown in FIG. 14.

As shown in FIG. 14, the vibration detection threshold value curvevaries depending on the receptor. Use of this characteristics alsoallows the time length Δt of the pre-drive (start timing of pre-drive)and the amplitude at the time of the pre-drive (drive signal strength ofpre-drive) to be dynamically determined on the basis of the mainfrequency components at the rise portion of the tactile signal and thecharacteristics of the receptors.

As a specific example, Merkel, indicated by the threshold value Th-m,has a relatively high perception threshold value. Moreover, Merkel has alow time responsiveness. Therefore, in a case where the rise portion ofthe tactile signal mainly includes low frequency components (e.g., 3 to2 Hz or less), the tactile stimulation corresponding to the rise portionis deemed to be perceived mainly by Merkel, the tactile presentationdevice 6 may be vibrated largely in advance, and a slight deviation ofthe stimulation presentation timing is allowed.

On the other hand, Pacinian, indicated by the threshold value Th-p, hasa low perception threshold value in a relatively high frequency band ofabout 200 Hz, and exhibits good sensitivity. Moreover, Pacinian has hightime responsiveness. Therefore, in a case where the rise portion of thetactile signal mainly includes high frequency components (e.g., 200 Hzor higher), the tactile stimulation corresponding to the rise portion isdeemed to be perceived mainly by Pacinian, and the amplitude at the timeof the pre-drive is reduced.

Here, it is conceivable that the encoding unit 24 performs the signalanalysis for identifying the main receptor that perceives the tactilestimulation at the rise portion. In that case, the encoding unit 24stores information indicating a main receptor that perceives tactilestimulation of the target rise portion for the header of the frame Fr,for example. On the basis of information indicating the main receptor,the decoding unit 34 determines the time length Δt of the pre-drive andthe amplitude at the time of the pre-drive.

Note that the signal analysis for identifying the main receptor thatperceives the tactile stimulation can also be performed on the decodingunit 34 side.

[1-8. Fourth Variation]

The description so far has been assumed that the time length Δt of thepre-drive and the amplitude of the pre-drive are calculated and acquiredin a predetermined manner by the decoding unit 34, but the time lengthΔt of the pre-drive and the amplitude at the time of the pre-drive maybe adjustable by operation to the user such as a toucher.

FIG. 15 shows an example of the graphical user interface (GUI) foradjustment.

Specifically, FIG. 15 shows an example of the GUI in a case where thereproduction device 3 has a display device such as a liquid crystaldisplay or an organic electro-luminescence (EL) display, and a touchscreen operator formed on a display screen 3 a of the display device.This figure shows an example of a configuration in which a slideroperator SL displayed on the display screen 3 a can adjust the length ofthe time length Δt of the pre-drive or the magnitude of the amplitude atthe time of the pre-drive.

This makes it possible to correspond to the user's preference and thetolerance degree of the deviation of the tactile stimulation timing.

2. SECOND EMBODIMENT

[2-1. Configuration of Tactile Reproduction System]

Next, the second embodiment will be described.

In the second embodiment, a plurality of the tactile sensors 5 and thetactile presentation devices 6 are provided to handle tactile signals ofa plurality of channels.

FIG. 16 is a diagram for explaining an internal configuration example ofan encoding device 2A as the second embodiment, and shows the pluralityof tactile sensors 5 together with the internal configuration example ofthe encoding device 2A.

The difference from the encoding device 2 shown in FIG. 2 is that,corresponding to the provision of the plurality of tactile sensors 5,the amplifier 21 and the A/D converter 22 are provided for every tactilesensor 5, and a preprocessing unit 23A and an encoding unit 24A areprovided in place of the preprocessing unit 23 and the encoding unit 24.

The preprocessing unit 23A inputs a tactile signal by a digital signaloutput from each A/D converter 22, and performs the similar signalprocessing to that of the preprocessing unit 23 for each tactile signal.

The encoding unit 24A inputs each tactile signal having been subjectedto the processing by the preprocessing unit 23A, and performs thesimilar encoding to that of the encoding unit 24 for the tactilesignals. The encoded data Dc in this case can be independent data foreach channel of a tactile signal, or can be data obtained bytime-division multiplexing the tactile signal of every channel in onestream.

The following description assumes that the encoded data Dc generated bythe encoding unit 24A is the stream data of the latter. In this case, inthe stream data, for every frame Fr of each channel, informationregarding the time T until rise and the rise height A is stored in theheader.

FIG. 17 is a diagram for explaining an internal configuration example ofa reproduction device 3A as the second embodiment, and shows theplurality of tactile presentation devices 6 together with the internalconfiguration example of the reproduction device 3A.

The difference from the reproduction device 3 illustrated in FIG. 3 isthat, corresponding to the provision of a plurality of the tactilepresentation devices 6, the amplifier 31 and the D/A converter 32 areprovided for every tactile presentation device 6, and a postprocessingunit 33A and a decoding unit 34A are provided in place of thepostprocessing unit 33 and the decoding unit 34.

On the basis of the data of the frame Fr for every channel in theencoded data Dc, the decoding unit 34A performs the similar decoding tothat of the decoding unit 34 for every channel to realize the pre-drivefor every channel, and performs power saving control of the amplifier 31for every channel.

The postprocessing unit 33A performs the similar signal processing tothat of the postprocessing unit 33 for the tactile signal of eachchannel to be output from the decoding unit 34A, and outputs eachtactile signal to the D/A converter 32 of the corresponding channel.

The tactile signal of each channel is converted into an analog signal bythe D/A converter 32 of the corresponding channel, and then output tothe tactile presentation device 6 of the corresponding channel via theamplifier 31 of the corresponding channel.

[2-2. First Application Example]

Here, since the human tactile sense is felt over a wide range of theentire body, it is conceivable to use a large number of the tactilepresentation devices 6 for stimulating the wide range also inpresentation of the tactile sense, and to present a wide band of tactileinformation by combining the plurality of tactile presentation devices 6having different frequency characteristics in order to present morevarious tactile senses.

Here, as a case of combined use of such different types of tactilepresentation devices 6, an example of use of a torso presentation typetactile device as shown in FIG. 18 will be shown.

In this torso presentation type tactile device, each tactilepresentation device 6 is disposed so as to be capable of presentingtactile stimulation to different sites in the torso of the human body.It is desirable that as many tactile presentation devices 6 as possiblebe disposed so that tactile information can be presented over a wideregion of the body.

Note that although FIG. 18 gives an example of a T-shirt type tactiledevice, it is possible to adopt a tactile device of another shape suchas a jacket type.

At present, the tactile presentation device 6 as a vibration device inparticular can only output vibrations in a narrow frequency band byitself, and in order to present tactile information with higher reality,it is conceivable to use the tactile presentation devices 6 havingdifferent frequency characteristics in combination, such as a linearactuator excellent in output of a low frequency and a piezoelectricelement (piezo element) excellent in output of a high frequency.

At this time, since the time responsiveness is different between thedifferent tactile presentation devices 6 having different frequencycharacteristics, the actual tactile timings can vary depending on thetactile presentation devices 6 even if the tactile signals of thetactile presentation devices 6 have a synchronized rise timing.

The drive method as the embodiment is effective also in preventing thedeviation of the tactile presentation timing between the tactilepresentation devices 6 of such different types.

Specifically, corresponding to the case where the different types oftactile presentation devices 6 are used in a mixed manner, the decodingunit 34A obtains the time length Δt corresponding to the responsivenessof the tactile presentation device 6 to be used for every channel. Thatis, for a channel in which a linear actuator is used as the tactilepresentation device 6, the time length Δt is calculated on the basis ofthe responsiveness and the rise height A of the linear actuator.Furthermore, for a channel in which a piezoelectric element (consideredto be higher in responsive than the linear actuator) is used as thetactile presentation device 6, the time length Δt is calculated on thebasis of the responsiveness and the rise height A of the piezoelectricelement.

Thus, by obtaining the time length Δt of the pre-drive in accordancewith the type (responsiveness) of the tactile presentation device 6 tobe used, it is possible to prevent an occurrence of variations in thetactile presentation timing among the tactile presentation devices 6 inspite of the synchronization of the rise timing on the tactile signalside. That is, the tactile presentation timing is synchronized among thedifferent types of tactile presentation devices 6.

Note that as shown in FIG. 18, each of the different types of tactilepresentation devices 6 can not only be disposed so as to give tactilestimulation to different sites of the human body, but also be disposedso as to give tactile stimulation to the same sites.

Furthermore, in the second embodiment, the amplitude (drive signalstrength) at the time of the pre-drive may be changed in accordance withthe type (responsiveness) of the tactile presentation device 6 to beused.

[2-3. Second Application Example]

Here, the different types of tactile presentation devices 6 havingdifferent frequency characteristics can give tactile stimulation toreceptors different from each other.

For example, Merkel, Meissner, and Pacinian receptors have differentfrequency bands where good response is exhibited. It is generally saidthat Merkel responds well in the low frequency, Meissner responds wellin the middle frequency, and Pacinian responds well in the highfrequency. Although the characteristics of these receptors do notnecessarily respond only to clearly divided bands, it is conceivablethat as an example, the low frequency is defined as less than 3 Hz inaccordance with Merkel's characteristics, the middle frequency as 3 Hzor more and less than 40 Hz in accordance with Meissner'scharacteristics, and the high frequency as 40 Hz or more and 1000 Hz orless in accordance with Pacinian's characteristics.

In this case, for the tactile presentation devices 6, three types oftactile presentation devices 6 for Merkel, Meissner, and Pacinianexhibiting good sensitivity in the low, middle, and high frequencies,respectively, are used.

The pre-drive of every of the different types of tactile presentationdevices 6 can be performed by varying the drive signal strength and thestart timing in accordance with the characteristics of the targetreceptor, specifically, the perception threshold value and the timeresponsiveness.

For example, the encoding unit 24A records, in the header of the frameFr, for every channel, identification information for identifying areceptor targeted by the tactile presentation device 6 of that channel.On the basis of the identification information, the decoding unit 34Aexecutes the pre-drive with the drive signal strength and the starttiming corresponding to the receptor for every channel.

Alternatively, it is not essential to store the identificationinformation in the encoded data Dc by encoding, and it is also possibleto adopt a configuration in which, on the basis of the signal analysisof the tactile signal, the decoding unit 34A specifies which receptor atactile signal is directed to, and executes the pre-drive with the drivesignal strength and the start timing corresponding to the specifiedreceptor.

Therefore, the pre-drive of every tactile presentation device 6 can beperformed in an appropriate mode corresponding to the characteristics ofthe target receptor, and it is possible to improve the reproducibilityof the tactile sense.

In particular, for a vibration device or the like, it is difficult toimplement the tactile presentation device 6 that exhibits goodsensitivity in a wide band from a low frequency to a high frequency, andtherefore, use of the tactile presentation device 6 having differentfrequency characteristics for every receptor as in this example iseffective in improving the reproducibility of the tactile sense.

[2-4. Third Application Example]

Human tactile characteristics can vary from site to site, and perceptionthreshold values such as vibration detection threshold values can alsovary in different sites such as the back and upper arms.

Therefore, it is also possible to make the amplitude (drive signalstrength) at the time of the pre-drive variable in accordance with thesite of the human body to which the tactile presentation device 6 ismounted. In this case, the encoding unit 24A records, in the header ofthe frame Fr, for every channel, identification information foridentifying a site to which the tactile presentation device 6 of thechannel is mounted. On the basis of the identification information, thedecoding unit 34A executes the pre-drive with the drive signal strengthcorresponding to the mounting site for every channel.

Therefore, the pre-drive of every tactile presentation device 6 can beperformed in an appropriate mode corresponding to the tactilecharacteristics of the target body site, and it is possible to improvethe reproducibility of the tactile sense.

3. VARIATIONS

Note that although the example of obtaining the time length Δt of thepre-drive and the start-up time Δta of the amplifier 31 on the decodingunit 34 (34A) side has been described above, it is also possible toobtain such information on the encoding unit 24 (24A) side on the basisof the signal analysis of the tactile signal, and record it into theencoded data Dc, and the decoding unit 34 (34A) performs the pre-driveand the control of the amplifier 31 on the basis of such storedinformation.

Furthermore, although a vibration device is exemplified as the tactilepresentation device 6 in the above description, it is also possible touse, as the tactile presentation device 6, a device that performstactile presentation by means other than vibration, such as, forexample, a device that performs tactile stimulation by air flow ordirect stimulation of a nerve by electricity, or a device that givestactile stimulation by ultrasonic waves. In particular, as the tactilepresentation device 6 that discharges air, one that has a pump fordischarging air is low in responsiveness, and the present technology canbe preferably applied.

4. SUMMARY OF EMBODIMENTS

As described above, the drive control device (reproduction devices 3 and3A) as an embodiment includes the drive control unit (F2 and thedecoding units 34 and 34A) that causes the drive unit (F1 and theamplifier 31) that drives the tactile presentation device by a drivesignal based on the tactile signal to execute a pre-drive, which is todrive the tactile presentation device in advance with respect to therise timing of the tactile signal.

By the pre-drive described above, a timing at which a tactilepresentation is actually started can be brought close to a rise timingof a tactile signal.

Therefore, it is possible to prevent delay in tactile presentationtiming due to the responsiveness of the tactile presentation device, andit is possible to improve the reproducibility of the tactile sense.

Furthermore, in a case where tactile presentation devices havingdifferent responsiveness such as an eccentric motor and a piezoelectricelement are used in combination, it is possible to absorb the differencein the response time between them and to synchronize the presentationstimulation.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit starts the pre-drive at a timing corresponding to theresponsiveness of the tactile presentation device.

This makes it possible to set a timing at which a tactile presentationis actually started to a timing corresponding to a responsiveness of atactile presentation device.

Therefore, it is possible to prevent delay in tactile presentationtiming due to the responsiveness of the tactile presentation device, andit is possible to improve the reproducibility of the tactile sense.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit starts the pre-drive at a timing corresponding to the riseheight of the tactile signal.

This makes it possible to set a timing at which a tactile presentationis actually started to a timing corresponding to a rise height of atactile signal.

Therefore, it is possible to prevent delay in tactile presentationtiming due to the responsiveness of the tactile presentation device, andit is possible to improve the reproducibility of the tactile sense.

Furthermore, in the drive control device as an embodiment, the tactilesignal is accompanied by timing-related information, which isinformation related to the timing of the pre-drive, by encoding, and thedrive control unit causes the drive unit to execute the pre-drive on thebasis of the timing-related information.

This eliminates the need for analysis of a tactile signal on thedecoding side when executing a pre-drive at an appropriate timing.

Therefore, it is possible to reduce the processing load on the decodingside.

Furthermore, in the drive control device as an embodiment, thetiming-related information includes information indicating the risetiming of the tactile signal.

This eliminates the need for signal analysis for detecting a rise timingof the tactile signal on the decoding side when executing a pre-drive atan appropriate timing.

Therefore, it is possible to reduce the processing load on the decodingside.

Furthermore, in the drive control device as an embodiment, thetiming-related information includes information indicating the riseheight of the tactile signal.

This eliminates the need for signal analysis for detecting a rise heightof a tactile signal on the decoding side when executing a pre-drive atan appropriate timing.

Therefore, it is possible to reduce the processing load on the decodingside.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit executes the pre-drive with the drive signal strengthcorresponding to the rise height of the tactile signal.

This makes it possible to prevent a delay of a presentation timing tothe toucher at the moment of the maximum amplitude at a rise portion ofa tactile signal.

Therefore, it is possible to improve the reproducibility of the tactilesense by preventing the perception delay at the moment of the maximumamplitude.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit executes the pre-drive with the drive signal strengthcorresponding to the perception threshold value related to the humantactile sense.

This makes it possible to match the timing at which a toucher starts toperceive tactile stimulation corresponding to a rise portion of atactile signal with an original timing.

Therefore, it is possible to improve the reproducibility of the tactilesense in terms of preventing the toucher from starting to percept thetactile sense before the original timing.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit executes the pre-drive with a drive signal strengthcorresponding to the lowest value of the perception threshold value.

This can prevent tactile stimulation from being perceived regardless ofa frequency component of a rise portion of a tactile signal.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit determines the start timing of the pre-drive in units offrames of the tactile signal.

This eliminates the need for timer management in units of samples of atactile signal when determining a start timing of a pre-drive.

Therefore, it is possible to reduce the processing load in order toprevent delay in the tactile presentation timing.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit determines a start timing of the pre-drive in units ofsamples of the tactile signal.

This makes it possible to improve an accuracy of a start timing of apre-drive.

Therefore, it is possible to increase the matching accuracy between thetiming at which tactile presentation is actually started and theoriginal timing, and it is possible to improve the reproducibility ofthe tactile sense.

Furthermore, in the drive control device as an embodiment, the drivecontrol unit sets the start timing of the pre-drive or the drive signalstrength on the basis of an operation.

This makes it possible for a system user such as a toucher to adjust astart timing of a pre-drive and a drive signal strength.

Therefore, it is possible to improve the customizability of theexecution mode of the pre-drive, and to improve the convenience of thetactile reproduction system.

Furthermore, in the drive control device as an embodiment, the driveunit drives the tactile presentation device by the drive signalamplified by the amplifier, and the drive control unit performs controlof bringing the amplifier into the power saving state on the basis ofthe amplitude value of the tactile signal, and performs control ofbringing the amplifier into the start-up state on the basis of the starttiming of the pre-drive.

This makes it possible to reduce power consumption caused by bringing anamplifier into a power saving state in a period other than a riseportion of a tactile signal in response to a case where a rise portionof a tactile signal exists discretely in a time direction, and to bringan amplifier into a start-up state before a start timing of a pre-drive.

Therefore, it is possible to improve the reproducibility of the tactilesense by pre-drive while reducing power consumption.

Furthermore, in the drive control device as an embodiment, the driveunit drives a plurality of tactile presentation devices, and the drivecontrol unit (34A) performs the pre-drive so that a tactile presentationtiming is synchronized among the plurality of tactile presentationdevices.

This makes it possible to prevent variation in tactile presentationtiming for each tactile presentation device in a case where a pluralityof tactile presentation devices having different responsiveness is used.

Therefore, it is possible to improve the reproducibility of the tactilesense.

Furthermore, in the drive control device as an embodiment, the driveunit drives the plurality of tactile presentation devices, each of whichperforming tactile presentation to a different receptor of the humanbody, and the drive control unit executes the pre-drive for each tactilepresentation device at the drive signal strength or start timingcorresponding to characteristics of the receptor.

This makes it possible to perform the pre-drive for each tactilepresentation device in an appropriate mode corresponding tocharacteristics of a target receptor in a case where a plurality oftactile presentation devices performs tactile presentation targetingdifferent receptors of a human body.

Therefore, it is possible to improve the reproducibility of the tactilesense.

Furthermore, in the drive control device as an embodiment, the driveunit drives the plurality of tactile presentation devices, and the drivecontrol unit executes the pre-drive for each tactile presentation devicewith the drive signal strength corresponding to the tactile presentationsite of the tactile presentation device in the human body.

This makes it possible to perform the pre-drive for each tactilepresentation device in an appropriate mode corresponding to tactilecharacteristics of a site of a human body in a case where a plurality oftactile presentation devices performs tactile presentation targetingdifferent sites of a human body.

Therefore, it is possible to improve the reproducibility of the tactilesense.

Furthermore, the drive control method as an embodiment is a drivecontrol method including causing the drive unit that drives the tactilepresentation device by the drive signal based on the tactile signal toexecute the pre-drive, which is to drive the tactile presentation devicein advance with respect to the rise timing of the tactile signal.

Such drive control method as an embodiment can also achieve similaroperations and effects to those of the drive control device as theembodiment described above.

The functions of the encoding units (24, 24A) and the decoding units(F2, 34, 34A) described above can be implemented as software processingby a CPU or the like. The software processing is executed on the basisof a program, and the program is stored in a storage device readable bya computer device (information processing device) such as a CPU.

The program as an embodiment is a program that causes the informationprocessing device to implement the function of causing the drive unitthat drives the tactile presentation device by the drive signal based onthe tactile signal to execute the pre-drive, which is to drive thetactile presentation device in advance with respect to the rise timingof the tactile signal.

With such program, it is possible to implement the drive control deviceas the embodiment described above.

Note that the effects described in the present description are merelyexamples and are not limited thereto, and other effects may be present.

5. PRESENT TECHNOLOGY

Note that the present technology can also have the followingconfiguration.

(1)

A drive control device including

a drive control unit that causes a drive unit that drives a tactilepresentation device by a drive signal based on a tactile signal toexecute a pre-drive, which is to drive the tactile presentation devicein advance with respect to a rise timing of the tactile signal.

(2)

The drive control device according to (1) described above, in which

the drive control unit starts

the pre-drive at a timing corresponding to a responsiveness of thetactile presentation device.

(3)

The drive control device according to (1) or (2) described abovedescribed above, in which

the drive control unit starts

the pre-drive at a timing corresponding to a rise height of the tactilesignal.

(4)

The drive control device according to any of (1) to (3) described above,in which

the tactile signal is accompanied by timing-related information, whichis information regarding a timing of the pre-drive, by encoding, and

the drive control unit causes

the drive unit to execute the pre-drive on the basis of thetiming-related information.

(5)

The drive control device according to (4) described above, in which

the timing-related information includes information indicating the risetiming of the tactile signal.

(6)

The drive control device according to (4) or (5) described above, inwhich

the timing-related information includes information indicating the riseheight of the tactile signal.

(7)

The drive control device according to any of (1) to (6) described above,in which

the drive control unit executes

the pre-drive with a drive signal strength corresponding to the riseheight of the tactile signal.

(8)

The drive control device according to any of (1) to (7) described above,in which

the drive control unit executes

the pre-drive with a drive signal strength corresponding to a perceptionthreshold value related to a human tactile sense.

(9)

The drive control device according to (8) described above, in which

the drive control unit executes

the pre-drive with a drive signal strength corresponding to a lowestvalue of the perception threshold value.

(10)

The drive control device according to any of (1) to (9) described above,in which

the drive control unit determines

a start timing of the pre-drive in units of frames of the tactilesignal.

(11)

The drive control device according to any of (1) to (9) described above,in which

the drive control unit determines

a start timing of the pre-drive in units of samples of the tactilesignal.

(12)

The drive control device according to any of (1) to (11) describedabove, in which

the drive control unit sets

the start timing of the pre-drive or the drive signal strength on thebasis of an operation.

(13)

The drive control device according to any of (1) to (12) describedabove, in which

the drive unit drives

the tactile presentation device by the drive signal amplified by anamplifier, and

the drive control unit performs

control of bringing the amplifier into a power saving state on the basisof an amplitude value of the tactile signal, and performs control ofbringing the amplifier into a start-up state on the basis of the starttiming of the pre-drive.

(14)

The drive control device according to any of (1) to (13) describedabove, in which

the drive unit drives

a plurality of the tactile presentation devices, and

the drive control unit performs

the pre-drive so that a tactile presentation timing is synchronizedamong the plurality of tactile presentation devices.

(15)

The drive control device according to any of (1) to (14) describedabove, in which

the drive unit drives

the plurality of tactile presentation devices, each of which performingtactile presentation to a different receptor of a human body, and

the drive control unit executes

the pre-drive for the each tactile presentation device at the drivesignal strength or start timing corresponding to characteristics of thereceptor.

(16)

The drive control device according to any of (1) to (15) describedabove, in which

the drive unit drives

the plurality of tactile presentation devices, and

the drive control unit executes

the pre-drive for the each tactile presentation device with the drivesignal strength corresponding to a tactile presentation site of thetactile presentation device in a human body.

REFERENCE SIGNS LIST

-   1 Tactile reproduction system-   2, 2A Encoding device-   3, 3A Reproduction device-   5 Tactile sensor-   6 Tactile presentation device-   Dc Encoded data-   21 Amplifier-   24, 24A Encoding unit-   24 a Signal analysis unit-   24 b Encoded data generation unit-   31 Amplifier-   32 D/A converter-   33, 33A Postprocessing unit-   34, 34A Decoding unit-   F1 Drive unit-   F2 Drive control unit-   3 a Display screen-   SL Slider operator

The invention claimed is:
 1. A drive control device comprising a drivecontrol unit that causes a drive unit that drives a tactile presentationdevice by a drive signal based on a tactile signal to execute apre-drive, which is to drive the tactile presentation device in advancewith respect to a rise timing of the tactile signal, wherein the driveunit drives the tactile presentation device by the drive signalamplified by an amplifier, and the drive control unit performs controlof bringing the amplifier into a power saving state on a basis of anamplitude value of the tactile signal, and performs control of bringingthe amplifier into a start-up state on a basis of a start timing of thepre-drive.
 2. The drive control device according to claim 1, wherein thedrive control unit starts the pre-drive at a timing corresponding to aresponsiveness of the tactile presentation device.
 3. The drive controldevice according to claim 1, wherein the drive control unit starts thepre-drive at a timing corresponding to a rise height of the tactilesignal.
 4. The drive control device according to claim 1, wherein thetactile signal is accompanied by timing-related information, which isinformation regarding a timing of the pre-drive, by encoding, and thedrive control unit causes the drive unit to execute the pre-drive on abasis of the timing-related information.
 5. The drive control deviceaccording to claim 4, wherein the timing-related information includesinformation indicating the rise timing of the tactile signal.
 6. Thedrive control device according to claim 4, wherein the timing-relatedinformation includes information indicating a rise height of the tactilesignal.
 7. The drive control device according to claim 1, wherein thedrive control unit executes the pre-drive with a drive signal strengthcorresponding to a rise height of the tactile signal.
 8. The drivecontrol device according to claim 1, wherein the drive control unitexecutes the pre-drive with a drive signal strength corresponding to aperception threshold value related to a human tactile sense.
 9. Thedrive control device according to claim 8, wherein the drive controlunit executes the pre-drive with a drive signal strength correspondingto a lowest value of the perception threshold value.
 10. The drivecontrol device according to claim 1, wherein the drive control unitdetermines a start timing of the pre-drive in units of frames of thetactile signal.
 11. The drive control device according to claim 1,wherein the drive control unit determines a start timing of thepre-drive in units of samples of the tactile signal.
 12. The drivecontrol device according to claim 1, wherein the drive control unit setsa start timing of the pre-drive or a drive signal strength on a basis ofan operation.
 13. The drive control device according to claim 1, whereinthe drive unit drives a plurality of the tactile presentation devices,and the drive control unit performs the pre-drive so that a tactilepresentation timing is synchronized among the plurality of tactilepresentation devices.
 14. The drive control device according to claim 1,wherein the drive unit drives a plurality of the tactile presentationdevices, each of which performing tactile presentation to a differentreceptor of a human body, and the drive control unit executes thepre-drive for the each tactile presentation device at a drive signalstrength or start timing corresponding to characteristics of thereceptor.
 15. The drive control device according to claim 1, wherein thedrive unit drives a plurality of the tactile presentation devices, andthe drive control unit executes the pre-drive for the each tactilepresentation device with a drive signal strength corresponding to atactile presentation site of the tactile presentation device in a humanbody.
 16. A drive control method comprising causing a drive unit thatdrives a tactile presentation device by a drive signal based on atactile signal to execute a pre-drive, which is to drive the tactilepresentation device in advance with respect to a rise timing of thetactile signal, wherein the drive unit drives the tactile presentationdevice by the drive signal amplified by an amplifier, and a drivecontrol unit performs control of bringing the amplifier into a powersaving state on a basis of an amplitude value of the tactile signal, andperforms control of bringing the amplifier into a start-up state on abasis of a start timing of the pre-drive.
 17. A non-transitory storagemedium encoded with instructions that, when executed by a computer,execute processing comprising causing an information processing deviceto implement a function of causing a drive unit that drives a tactilepresentation device by a drive signal based on a tactile signal toexecute a pre-drive, which is to drive the tactile presentation devicein advance with respect to a rise timing of the tactile signal, whereinthe drive unit drives the tactile presentation device by the drivesignal amplified by an amplifier, and a drive control unit performscontrol of bringing the amplifier into a power saving state on a basisof an amplitude value of the tactile signal, and performs control ofbringing the amplifier into a start-up state on a basis of a starttiming of the pre-drive.